Outdoor decks and similar structures are often constructed from elongate support members such as wooden joists over which a decking material is placed. In many instances, the space beneath such decks and similar structures does not provide usable storage room due to water leakage through the decking material during rainstorms or when accumulated snow and ice on the deck melts. Thus, there exists a need for a system, tools and a method for diverting water that may leak though a deck, roof or similar structure from leaking through the structure to the area beneath the structure.